Multidrug Resistant Bacteria Causing Nosocomial Urinary Tract Infection in Neurology/ Neurosurgical Unit of a Tertiary Care Hospital

Introduction: Nosocomial infections with the multidrug resistant microorganisms remain the major concern in the hospitalized patients. Due to the underlying illness, trauma, various neurosurgeries, patients admitted to neurology/ neurosurgery units become more vulnerable to acquire device associated infections during their hospital stay. Objectives: To study the spectrum of uropathogens and their antimicrobial susceptibility pattern among patients admitted to the neurology/neurosurgery unit. Material and methods: A prospective study was conducted in the bacteriology laboratory, Department of Microbiology over a period of 4 months. Urine samples from the patients admitted to neurology and neurosurgical unit (ward and ICU) were processed and identified as per the standard protocol. The antimicrobial susceptibility testing was done using Kirby- Bauer method as per CLSI 2014 guideline. Results: Majority of the urinary isolates belonged to Enterobacteriaceae family in both ward and ICU patients. Among these, 91 out of 106 (86%) isolates in the ward and 43 out of 51 (84%) isolates in ICU were found to be multi drug resistant. Nitrofurantoin was observed to be resistant in more than 75% of both ward and ICU isolates. Conclusion: Majority of nosocomial uropathogens were found to be multidrug resistant. This study emphasizes the emergence of MDR isolates and nitrofurantoin resistance among the nosocomial uropathogens

Strategy for identification & characterization of Bartonella henselae with conventional & molecular methods

Background & objectives: Bartonella henselae is a fastidious gram-negative bacterium usually causing self limiting infections in immunocompetent individuals but often causes potentially life threatening infection, such as bacillary angiomatosis in immunocompromised patients. Both diagnosis of infections and research into molecular mechanisms of pathogenesis have been hindered by lack of appropriate and reliable diagnostic techniques. We undertook this study to standardize methods to characterize B. henselae in clinical samples to diagnose Bartonella infection correctly. Methods: B. henselae ATCC 49882 strain was procured from American type culture collection, USA. This strain was revived and maintained in the laboratory, and identification and characterization of this strain was done by conventional and molecular techniques, which included culture on various media, staining by different methods including electron microscopy, biochemical analysis by conventional methods and API, polymerase chain reaction (PCR) for amplification of citrate synthase gene followed by restriction fragment length polymorphism (RFLP). Results: This organism was biochemically inert due to slow growth and generated unique identification code with API. The amplification of the citrate-synthase gene with primers yielded a 381 bp product followed by specific RFLP profile for B. henselae. Interpretation & conclusions: Bartonella is fastidious and fragile organism and should be handled carefully. Extra effort and careful observation are required to isolate and characterize this organism

Combination of alpha-melanocyte stimulating hormone with conventional antibiotics against methicillin resistant Staphylococcus aureus.

Our previous studies revealed that alpha-melanocyte stimulating hormone (α-MSH) is strongly active against Staphylococcus aureus (S. aureus) including methicillin resistant S. aureus (MRSA). Killing due to α-MSH occurred by perturbation of the bacterial membrane. In the present study, we investigated the in vitro synergistic potential of α-MSH with five selected conventional antibiotics viz., oxacillin (OX), ciprofloxacin (CF), tetracycline (TC), gentamicin (GM) and rifampicin (RF) against a clinical MRSA strain which carried a type III staphylococcal cassette chromosome mec (SCCmec) element and belonged to the sequence type (ST) 239. The strain was found to be highly resistant to OX (minimum inhibitory concentration (MIC) = 1024 µg/ml) as well as to other selected antimicrobial agents including α-MSH. The possibility of the existence of intracellular target sites of α-MSH was evaluated by examining the DNA, RNA and protein synthesis pathways. We observed a synergistic potential of α-MSH with GM, CF and TC. Remarkably, the supplementation of α-MSH with GM, CF and TC resulted in ≥ 64-, 8- and 4-fold reductions in their minimum bactericidal concentrations (MBCs), respectively. Apart from membrane perturbation, in this study we found that α-MSH inhibited ≈ 53% and ≈ 47% DNA and protein synthesis, respectively, but not RNA synthesis. Thus, the mechanistic analogy between α-MSH and CF or GM or TC appears to be the reason for the observed synergy between them. In contrast, α-MSH did not act synergistically with RF which may be due to its inability to inhibit RNA synthesis (<10%). Nevertheless, the combination of α-MSH with RF and OX showed an enhanced killing by ≈ 45% and ≈ 70%, respectively, perhaps due to the membrane disrupting properties of α-MSH. The synergistic activity of α-MSH with antibiotics is encouraging, and promises to restore the lost potency of discarded antibiotics